SOUND POST HAVING A VARIABLE LENGTH

Abstract

A sound post, particularly for string instrument, having a variable length is described. The sound post consists of a first tubular component having a first end and a second end and a second tubular component having a first end and a second end, wherein the second tubular component is at least partially arranged in the first tubular component in a movable manner, and wherein a first pivotable end piece is arranged at the first end of the first tubular component. The sound post also comprises a counter-element and a tension fastener element which is rotatably arranged and suitable to be countered against the counter-element by rotation. A pivotable end piece is also arranged at the second end of the second tubular component. A sound post tool set for mounting the sound post in an instrument and a method for mounting the sound post in an instrument are also disclosed.

Claims

1. A sound post (1) having a variable length, comprising: a first tubular component (2) having a first end and a second end, a second tubular component (3) having a first end and a second end, wherein the second tubular component (3) is at least partially arranged in the first tubular component (2) in a movable manner, wherein a first pivotable end piece (5) is arranged at the first end of the first tubular component (2), and the second end of the first tubular component (2) serves as a counter-element (8), and wherein the first end of the second tubular component (3) comprises an outer thread at which a tension fastener element (7a) is rotatably arranged and which is suitable to be countered against the counter-element (8) by rotation, and a second pivotable end piece (6) is arranged at the second end of the second tubular component (3), and wherein the first pivotable end piece (5) and the second pivotable end piece (6) are made at least partially of a magnetizable material or as magnets.

2. A sound post (1) having a variable length, comprising: a first tubular component (2) having a first end and a second end, a second tubular component (3) having a first end and a second end, wherein the second tubular component (3) is at least partially arranged in the first tubular component (2) in a movable manner, wherein a first pivotable end piece (5) is arranged at the first end of the first tubular component (2), and the second end of the first tubular component (2) comprises an outer thread at which a tension fastener element (7a) is rotatably arranged, and wherein a counter-element (8) with a second pivotable end piece (6) is arranged at the second end of the second tubular component (3), and wherein the first pivotable end piece (5) and the second pivotable end piece (6) are made at least partially of a magnetizable material or as magnets.

3. A sound post (1) having a variable length, comprising: a first tubular component (2) having a first end and a second end, a second tubular component (3) having a first end and a second end, wherein the second tubular component (3) is at least partially arranged in the first tubular component (2) in a movable manner, and an elastic member (4) coupled to the first end of the second tubular component (3) is arranged within the first tubular component (2), and wherein a first pivotable end piece (5) is arranged at the first end of the first tubular component (2), and the second end of the first tubular component (2) serves as a counter-element (8), and wherein the first end of the second tubular component (3) comprises an outer thread at which a tension fastener element (7a) is rotatably arranged and which is suitable to be countered against the counter-element (8) by rotation, and a second pivotable end piece (6) is arranged at the second end of the second tubular component (3).

4. A sound post (1) having a variable length, comprising: a first tubular component (2) having a first end and a second end, a second tubular component (3) having a first end and a second end, wherein the second tubular component (3) is at least partially arranged in the first tubular component (2) in a movable manner, and an elastic member (4) coupled to the first end of the second tubular component (3) is arranged within the first tubular component (2), and wherein a first pivotable end piece (5) is arranged at the first end of the first tubular component (2), and the second end of the first tubular component (2) comprises an outer thread at which a tension fastener element (7a) is rotatably arranged, and wherein a counter-element (8) with a second pivotable end piece (6) is arranged at the second end of the second tubular component (3).

5. The sound post (1) according to claim 2, wherein the first tubular component (2) comprises a resting member (7b) at its outer side.

6. The sound post (1) according to claim 1, wherein the second tubular component (3) comprises a resting member (7b) at its second end.

7. The sound post (1) according to claim 1, wherein an elastic member (4) coupled to the first end of the second tubular component (3) is arranged within the first tubular component (2).

8. The sound post (1) according to claim 1, wherein one or more of the first and the second tubular components (2, 3) and the pivotable end pieces (5, 6) are made of wood.

9. The sound post (1) according to claim 1, wherein one or more of the first and the second tubular components (2, 3) and the pivotable end pieces (5, 6) are made of plastic.

10. The sound post (1) according to claim 1, wherein one or more of the first and the second tubular components (2, 3) and the pivotable end pieces (5, 6) are made of fiber-reinforced plastic.

11. The sound post (1) according to claim 1, wherein the first pivotable end piece (5) and the second pivotable end piece (6) are at least partially coated with a magnetic material.

12. The sound post (1) according to claim 1, wherein the second tubular component (3) comprises a continuous bore (10) arranged transversally to the longitudinal axis of the tubular component (3) between the second end piece (6) and its first end.

13. The sound post (1) according to claim 3, wherein the elastic member (4) is a spring and/or a foamed material and/or consists of two repelling magnets.

14. The sound post (1) according to claim 1, wherein at least one of the tension fastener element (7a) and the resting member (7b) are of metal or plastic.

15. The sound post (1) according to claim 1, wherein at least one of the tension fastener elements (7a) and the resting members (7b) has a polygonal, preferably octagonal, cross-section.

16. The sound post (1) according to claim 1, wherein the first tubular component (2) and the second tubular component (3) are substantially cylindrical.

17. The sound post (1) according to claim 1, characterized in that wherein each end piece (5, 6) comprises a partially spherical section (5a, 6a) and a flat end surface (5b, 6b) and the first tubular component (2) at its first end and the second tubular component (3) at its second end each comprise a partially spherical recess in which the respective partially spherical section (5a, 6a) is received.

18. A sound post tool set for mounting a sound post (1) having a variable length between the top and the back plate of a string instrument, comprising: a sound post (1) according to claim 1, and at least one adjusting tool (11) comprising a fork-like portion (12), a shaft (13) and a holding portion (14), wherein the shaft (13) is arch-shaped and has a length that corresponds at least to a length of a distance between a predetermined f-hole of the string instrument and a position at a string instrument back plate predetermined for the sound post (1).

19. The sound post tool set according to claim 18, additionally comprising furthermore two magnets a first magnet and a second magnet suitable to be respectively moved externally along the back and the top plate of the string instrument, respectively, in order to set upright and/or to position the sound post (1).

20. A method for mounting a sound post (1) according to one of in or out of a string instrument by means of a sound post adjusting tool, comprising the following steps: providing a sound post (1) according to claim 3, the sound post (1) being set at a predetermined length selected so that the length of the sound post (1) in a relaxed state is greater than the distance between the back and the top plate of the string instrument and in a compressed state, when a force is exercised against both end pieces (5, 6), is less than the distance between the back and the top plate of the string instrument, providing a sound post adjusting tool (11) comprising a fork-like portion (12), a shaft (13) and a holding portion (14), wherein the shaft (13) is arch-shaped and has a length that corresponds at least to a length of a distance between a predetermined f-hole of the string instrument and a position at a string instrument back plate predetermined for the sound post (1), inserting the sound post (1) in a relaxed state through an f-hole of the string instrument, and fitting the sound post (1) in a position predetermined within the string instrument by wedging the sound post (1) at an angle between the back and the top plate of the string instrument and compressing the elastic member (4) and positioning the sound post (1) vertically between the back and the top plate of the string instrument, inserting an the sound post adjusting tool (11) in an f-hole and fixing the length of the sound post (1) by rotating the tension fastener element (7a) with the sound post adjusting tool (11) against the counter-element (8).

21. A method for mounting a sound post (1) in or out of a string instrument by means of a sound post adjusting tool, comprising the following steps: providing a sound post (1) according to claim 1, the sound post (1) being set at having a predetermined length selected so that the total length of the first tubular component (2) and the second tubular component (3) of the sound post (1) in the extended state is greater than the distance between the back and the top plate of the string instrument, providing a sound post adjusting tool (11) comprising a fork-like portion (12), a shaft (13) and a holding portion (14), wherein the shaft (13) is arch-shaped and has a length that corresponds at least to a length of a distance between a predetermined f-hole of the string instrument and a position at a string instrument back plate predetermined for the sound post (1), providing a first magnet and a second magnet suitable to be respectively moved externally along the back and the top plate of the string instrument, respectively, in order to set upright and/or to position the sound post (1), inserting the sound post (1) through an f-hole of the string instrument, and setting upright the sound post (1), in a retracted state, and preliminary fitting it the sound post (1) in a position predetermined within the string instrument by applying and moving one of the first magnet externally along the back and the top plate of the string instrument, and rotating the instrument in such a way that the preliminary positioned sound post, in a retracted state, is extended between the back and the top plate of the string instrument due to gravity, and applying the second magnet externally on the back or the top plate of the string instrument opposite the first magnet and to the position of the extended sound post, and finally positioning the extended sound post by moving both the first magnet and the second magnet externally along the back and the top plate of the string instrument, and inserting the sound post adjusting tool (11) in an f-hole and fixing the length of the sound post (1) by rotating the tension fastener element (7a) with the sound post adjusting tool (11) against the counter-element (8).

22. Theound post (1) according to claim 10, wherein one or more of the first and the second tubular components (2, 3) and the pivotable end pieces (5, 6) are made of carbon fiber-reinforced plastic.

23. The sound post (1) according to claim 15, wherein at least one of the tension fastener elements (7a) and the resting members (7b) has an octagonal cross-section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] FIG. 1 shows a longitudinal cross-section of a first exemplary embodiment of a sound post according to the invention without an elastic member,

[0047] FIG. 2 shows a longitudinal cross-section of a second exemplary embodiment of a sound post according to the invention with an elastic member, and

[0048] FIG. 3 shows a schematic view of an adjusting tool of the sound post tool set.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0049] The embodiments of the sound post according to the invention illustrated in the figures relate to a sound post having a variable length for string instruments. As illustrated at the beginning, the sound post according to the invention can also be utilized in other instruments, for example, guitars, zithers or hammered dulcimers or similar instruments in order to advantageously influence the stability and the sound of the instrument, for example.

[0050] The FIGS. 1 and 2 show, respectively, an embodiment of a sound post having a variable length according to the invention, particularly as it can be used for string instruments. The sound post according to the invention consists of a first tubular component 2 having a first end and a second end and a second tubular component 3 having a first and a second end, wherein the second tubular component 3 according to an embodiment is displaceable against the force of an elastic member 4 in the first tubular component 2 in the longitudinal direction of the tubular component 2. A first pivotable end piece 5 is arranged at the first end of the first tubular component 2, and a second pivotable end piece 6 is arranged at the second end of the second tubular component. By pivoting the first and the second end pieces 5, 6, it is ensured that the end surfaces of the end pieces are perfectly fitted to the inner surfaces of the top and the back plate of the string instrument. Since the first and the second end pieces 5, 6 are formed pivotably, these end pieces can be perfectly fitted to the inner surfaces of the top and the back plate of the string instrument even if the top or the back plates are curved and their inner surfaces are thus not parallel. Due to elastic bedding of the second tubular component 3 in the first tubular component 2, the length of the sound post can be shortened by pressure on the first and the second pivotable end pieces 5, 6, thus facilitating the mounting of the sound post inside the string instrument. When pressure on the first and the second pivotable end pieces 5, 6 is released inside the string instrument, the sound post gets extended, its length increases, and the first and the second pivotable end pieces 5, 6 are pushed by the force of the elastic member 4 from below against the back and the top plate of the string instrument so that the sound post can not fall down when being mounted even at a temporary position inside the string instrument, for example. If the sound post according to the invention is arranged in the proper position within the string instrument, the sound post according to the invention comprises a tension fastener element 7a which can be countered against the counter-element 8 so that the sound post in the secured state has a fixed length, and the elastic power of the elastic member 4 is disabled in this state. In the embodiment in FIG. 1, the tension fastener element 7a is rotatably connected to the second tubular component 3 by means of an outer thread at the first end of the second tubular component 3 for the purpose of fixing the length of the sound post and can be countered against the second end of the first tubular component 2 by means of rotation. As evident from FIG. 1, the edge of the second end of the first tubular component 2 acts in this case as a counter-element 8. With the aid of the outer thread at the first end of the second tubular component 3 and the tension fastener element 7a, the length of the sound post according to the invention can be fixed. By means of this adjustment and fixing the length of the sound post, both the sound of the instrument and the stability can be persistently improved. The outer thread and the correspondingly adapted thread of the tension fastener element 7a can hereby be a standardized metric thread, for example M2 to M10, or a special fine thread in order to be able to precisely adjust the length of the sound post according to the invention.

[0051] In the embodiment of FIG. 2, the length of the sound post according to the invention is fixed with the help of an outer thread arranged at the second end of the first tubular component 2 and a corresponding tension fastener element 7a which is rotatably arranged at this outer thread. As evident from FIG. 2, the tension fastener element 7a according to the embodiment of FIG. 1 is countered against the counter-element 8 arranged at the second end of the second tubular component 3 so as to fix the length of the sound post.

[0052] In the embodiment shown in FIG. 1, the sound post 1 having a variable length does not comprise the elastic member 4. In this embodiment, the first pivotable end piece 5 and the second pivotable end piece 6 are made at least partially of a magnetizable material or as magnets. Thereby, for inserting the sound post 1 in the instrument, the second tubular component 3 can be pushed into the first tubular component 2 (a retracted state) and after having been inserted into the instrument it can be set upright by means of one and/or two magnets from the outside of the instrument. For setting upright the sound post 1, in a retracted state, and preliminary fitting it in a position predetermined within the string instrument, a magnet of a sound post tool set can be applied externally on the back or the top plate of the string instrument and correspondingly moved. The temporary positioned sound post, in a retracted state, gets extended by rotating the instrument so that the first tubular component 2 and the second tubular component 3 are pulled apart due to gravity and get fixed between the back and the top plate of the string instrument.

[0053] According to a further embodiment, even in the embodiment with the first pivotable end piece 5 and the second pivotable end piece 6, at least partially formed of a magnetizable material or as magnet, an elastic member 4 can be additionally arranged in the first tubular component 2.

[0054] The elastic member 4 can be, for example, a spring element such as a coil spring, a pneumatic spring or a kind of damper so that the first and the second tubular component act as a shock absorber, or it can be made of rubber, natural rubber, or the elastic member can be made of a foamed material, for instance foam or the like. A foamed material has the advantage compared to a coil spring that, for example, it does not transfer vibrations when playing the instrument and thus is absolutely noise-damped. Two repellent magnets can also be used as elastic member, for example. As disclosed above and seen from FIGS. 1 and 2, the elastic member 4 is arranged in the first tubular component 2 and coupled to the first end of the second tubular component 3. Hereby, it is clear that it must not necessarily be a direct coupling and that any intermediate members can be arranged between the elastic member 4 and the first end of the second tubular component or also between the elastic member 4 and the first end of the first tubular component. Moreover, the elastic member 4 could be made of a combination of different elastic members, for example the combination of a foamed material and a coil spring. In a further embodiment, the elastic member 4 can be coupled to the first end of the second tubular component 3 and to the first end of the first tubular component 2, i.e. at both ends. This prevents the components from falling apart when the sound post 1 is inserted before it gets wedged between the back and the top plate.

[0055] According to the present invention, the tension fastener element 7a is countered against the counter-element 8 for fixing the length of the sound post along an outer thread. For rotation of the tension fastener element 7a, the tension fastener element 7a comprises a correspondingly shaped outer surface in order to allow for rotation. This outer surface can, for example, be simply roughened as in a knurled screw or be slotted or have a polygonal cross-section in order to be rotated with a correspondingly shaped adjusting tool. This polygonal cross-section can, for example, be square or octagonal or even comprise more edges in order to allow for the smallest possible rotation angles, for example. Since the room for moving an adjusting tool 11 inserted through the f-hole of a string instrument is, for example, very scarce, it is advantageous to provide the tension fastener element with a big amount of edges in order to allow for small rotation angles, as well.

[0056] To avoid twisting the first tubular component or the second tubular component 3 when countering the tension fastener element against the counter-element 8, the sound post according to the invention can comprise a resting member 7b. As shown in FIG. 1, the sound post according to the first embodiment can comprise said resting member at the first end of the second tubular component 3, for example, as polygonal cross-section at the first end of the second tubular component 3 or even as a bore 10. In the embodiment according to FIG. 2, the resting member can be arranged at the outer side of the first tubular component 2. To arrange the resting member 7b, it is advantageous to determine its position so that it could be possible to reach it with an adjusting tool. That means that the resting member 7b shall be arranged along the tubular component in such a way that it could be easily accessible with an adjusting tool through an f-hole of the string instrument.

[0057] Wood, plastic, fiber-reinforced plastic, preferably carbon fiber reinforced plastic or, for example, metals such as aluminum, magnesium or alloys or combinations thereof can be used as materials for one or more of the first and the second tubular components and the pivotable end pieces of the sound post according to the invention. The tension fastener element 7a and/or the resting member 7b can also be made of another material than the first and the second tubular component, for example, of metal or plastic. According to one embodiment, the first pivotable end piece 5 and the second pivotable end piece 6 are made at least partially of a magnetizable material or as magnets. For this purpose, according to a further embodiment, the first pivotable end piece 5 and the second pivotable end piece 6 can be at least partially coated with a magnetic material.

[0058] To facilitate positioning of the sound post inside the string instrument or in the function of a resting member 10, the second tubular component 3 can comprise a continuous bore 10 arranged transversally to the longitudinal axis of the tubular component 3 between the second end piece 6 and its first end. To insert the sound post according to the invention, a thread can be passed through from one f-hole into the other f-hole of the string instrument, and the sound post can be attached to this thread through the continuous bore 10. Attached to this thread, the sound post 1 according to the invention can then be guided to the desired position inside the string instrument so that the continuous bore can prevent the sound post from falling down inside the instrument as well.

[0059] The first and the second pivotable end pieces 5, 6 of the sound post according to the invention can each comprise a partially spherical section 5a, 6a and a flat end surface 5b, 6b, and the corresponding ends of the first tubular component 2 and the second tubular component 3 can each comprise partially spherical recesses to receive the respective partially spherical section of the corresponding end piece 5, 6. Due to the fact that the sections of the end pieces and the recess of the corresponding sides of the first and the second tubular component are implemented in a partially spherical form, a large pivoting range can be realized to make it possible to adapt to the curvature inside an instrument to ensure a snug fit of the flat end surface 5b, 6b of the respective end piece 5, 6 to the corresponding back or top plate inside the string instrument. To prevent the end pieces 5, 6 from falling down from the corresponding ends of the first and the second tubular component 2, 3, the corresponding edge of the corresponding end of the first and the second tubular component can be formed in such a way that it partially encloses the partially spherical section 5a, 6a of the end pieces 5, 6 so that clip fixing can prevent them from falling out when assembling the sound post according to the invention.

[0060] The first and the second end pieces 5, 6 can, for example, be also formed magnetically in order to be able to be positioned from the outside by means of a magnet applied externally on the top and/or back plate, for example. The fact that the first and the second end pieces are formed magnetically has a further advantage in that the position of the set sound post can be easily displayed by flat detectors on the outer side of the string instrument.

[0061] FIG. 3 shows an embodiment of an adjusting tool 11 of a sound tool set according to the invention for mounting a sound post having a variable length between the top and the back plate of a string instrument. The adjusting tool 11 comprises a fork-like portion 12, a shaft 13 and a holding portion 14. The shaft 13 can hereby be arch-shaped and have a length that corresponds at least to a length of a distance between a predetermined f-hole of the string instrument and a position at a string instrument back plate predetermined for the sound post 1. The fork-like portion 12 can be formed in such a way that it perfectly encompasses the tension fastener element 7a and/or the resting member 7b in order to be able to rotate or hold these correspondingly.

[0062] For precisely positioning the sound post and correcting the position, the “sound post setter” used in violin making can also be used.

[0063] For precisely positioning the sound post and correcting its position, the sound post tool set according to an embodiment can moreover comprise two magnets suitable to be respectively moved externally along the back and the top plate of the string instrument, respectively, in order to set upright and/or to position the sound post (1).

[0064] According to an embodiment, the mounting a sound post according to the invention by means of a sound post tool set according to the invention comprises the steps of providing a sound post having a predetermined length selected so that the length of the sound post in an relaxed state is greater than the distance between the back and the top plate of the string instrument and in a compressed state, when a force is exercised against both end pieces (5, 6), is less than the distance between the back and the top plate of the string instrument. By inserting the relaxed sound post through an f-hole of the string instrument and temporarily wedging the sound post at an angle between the back and the top plate of the string instrument and by compressing the elastic member (4) and positioning the sound post vertically between the back and the top plate, the sound post can be positioned at a position predetermined within the string instrument. If required, the sound post positioned as described above, which is wedged between the back and the top plate by spring force of the elastic member 4, can be further corrected in its position with a sound post setter or an adjusting tool 11. Here, it is advantageous, among other things, that even a temporarily mounted sound post cannot fall down thanks to the spring force. When the sound post 1 is set to the correct position, one inserts an adjusting tool 11 in an f-hole and fixes the length of the sound post 1 by rotation (countering) the tension fastener element 7a with the adjusting tool 11 against the counter-element 8. To avoid twisting the first or the second tubular component, a second adjusting tool 11 can for example be also inserted through the second f-hole of the string instrument, and a resting member 7b can be held tightly in place.

[0065] According to a further embodiment, the mounting of a sound post according to the invention by means of a sound post tool set according to the invention comprises providing a sound post 1 having a predetermined length selected so that the total length of the first tubular component 2 and the second tubular component 3 of the sound post 1 in the extended state is greater than the distance between the back and the top plate of the string instrument, and inserting the sound post 1 through an f-hole of the string instrument. The retracted sound post 1 is set upright and preliminary fitted in a position predetermined within the string instrument by applying and moving one of the magnets of the sound post tool set externally along the back and the top plate of the string instrument. By rotating the instrument, the preliminary positioned sound post, in a retracted state, gets extended between the back and the top plate of the string instrument due to gravity. The method also comprises applying the second magnet of the sound post tool set externally on the back or the top plate of the string instrument opposite the first magnet and to the position of the extended sound post, and finally positioning the extended sound post by moving both magnets of the sound post tool set externally along the back and the top plate of the string instrument. By inserting an adjusting tool 11 in an f-hole, the length of the sound post 1 can be fixed by rotating the tension fastener element 7a with the adjusting tool 11 against the counter-element 8. To change the position and/or the length of a fixed sound post (e.g. in case of permanently changing temperature and/or air humidity, e.g. due to dry heating air in winter), a magnet must merely be applied externally on each side of the instrument at the position of the sound post. These magnets then hold the sound post in its position in an extended state even in case of a relaxed tension fastener element 7a, so that the position of the extended but relaxed sound post can then be corrected from outside of the instrument by moving the magnets and/or its length can be changed by rotation the tension fastener element 7a.

[0066] According to a particularly advantageous embodiment, the counter-element 8 can be labeled to mark the position of twisting of the counter-element in relation to the tension fastener element 7a. A particularly simple form of labeling could be marking the counter-element and the tension fastener element 7a with spots of color to mark the “neutral”, i.e. the position with the lowest tension, or the “optimal” position, for example. For this, different colors can for example be used, e.g. a white dot for the optimal setting in winter and a red one for summer. The labeling type is however not restricted to colors; for example, lines of different length can also be used for marking.

[0067] Thanks to the variable length of the sound post according to the invention and, particularly, thanks to the simple process of fixing of the length, the sound post, particularly its length, can be easily adjusted, for example, also in case of changing room temperature, e.g. between summer and winter, so that the best sound quality of the string instrument can be achieved in every season or at any humidity level. As soon as the correct position inside the instrument has been set, the sound post can remain in this position and, for example, its length can only be optimized with the aid of adjusting tools 11.

[0068] The invention is not limited to the specific illustrated embodiments, and actually the scope of the invention is determined by the subject-matter of the claims.